The invention relates to a coupling assembly having at least one friction coupling unit which comprises a driveable housing and a hub to be driven, and having differential-speed-dependent actuating means operated by a pressure agent and comprising a pump unit. The pump unit comprises housing parts and hub parts, which housing parts are rotatable relative to the hub parts, with the one part of the pump unit being connected in a rotationally fixed way to the housing of the friction coupling unit and the other parts of the pump unit being connected in a rotationally fixed way to the hub of the friction coupling unit.
A vehicle axle module with two such coupling assemblies is known from U.S. Pat. No. 4,960,011 wherein the axle housing comprises two cast-on axle tube projections in which axle shafts are supported directly by means of a differential carrier so as to be coaxially aligned. The assembly is obviously provided for rigid rear axles wherein the axle housing, as a whole, is suspended resiliently relative to a vehicle.
More widespread use is found for axle designs wherein the axle housing is fixedly arranged at the vehicle and wherein the wheels are driven by means of driveshafts with inner joints arranged at the axle housing and with outer joints arranged at the wheels. In the case of vehicles with small dimensions there exists a problem in that the space available for the driveshafts is so small that it is necessary to use joints with large joint angles, such joints being expensive and of a particularly high quality. This problem is particularly prevalent in the case of steerable axles wherein the joints not only have to accommodate the spring travel, but also the steering angle. This may lead to restrictions regarding the spring travel and the steering angle if joints with sufficiently large joint angles are not available.
It is therefore the object of the present invention to provide a coupling assembly of the initially mentioned type for propeller shafts, vehicle axle modules or the like, which coupling assembly, while having a simpler design, permits a longer spring travel and greater steering angles.